<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <div id="wrap">hello</div>
  <script>
    let myEvent = new Event('aaa', {
      "bubbles": true,
      "cancelable": true
    })
    document.getElementById('wrap').addEventListener('aaa', () => {
      console.log('hello world');
    })
    document.getElementById('wrap').dispatchEvent(myEvent)
  </script>
</body>

</html>